Hi guys, quick question. Is there such a thing as a high performance mechanical fuel pump for a Chevrolet 250? Is it necessary for a mild build (intake, headers, cam, etc)? If not, what brand should I get for an OEM replacement? Thank you.
I saw somewhere that a hipo V8 pump could be adapted to an inline by changing the arm. Do a Google search and it will probably turn up, or somebody else may chime in with a more definitive description.
I used to live in Florida where it got pretty hot during the summer, and if my car (stock 230 engine) sat for just 2 days, the fuel bowl would be too low or empty to fire up right away. It took a little too long to start the engine, for my liking. I installed an electric pump, it primes the carb in seconds, and fires right up after that. Never going back to a mechanical pump.
So far I haven't seen the need: Offy intake, Holley 390 and Langdon headers. Haven't done a cam yet or intake manifold work but I'm just fine with the fuel.
I have never run out of fuel with stock pumps on my sixes. I'm not racing, street only.
Two more quick questions:
- What is the difference between the mechanical pump that has threaded inlets & outlets, and the pumps that have the cheesy 90-degree barb fitting?
- Most of the mechanical pumps for sale state an operating pressure of about 4psi, Holley states the minimum for a 390 is 5psi. Can someone expand on this please?
Thank you.
A stock fuel pump has always been just fine for the Holley 390 on my 250. However, I had to replace stock fuel pumps pretty regularly, and they never seem to fail while in the driveway, lol. I suspect they failed due to regular runs up to 5-6,000 RPM which they weren't designed for. I switched to an electric pump and never had a problem after that.
I picked this up along the way....
This setup is also what I did...Just some more good info on mechanical fuel pumps... if you want to run a 4bbl or double pumper you should run the fuel pump off of a 1984 L6 250 which had a base pressure of 68psi instead of the 46psi of all earlier L6 250 mechanical pumps. As well boost referenced mechanical pumps are good to 1214lbs of boost after that, they cant keep up.
You don't run any more then 6psi to a holley.